The main purpose of this paper is to analyze the stability for a fuzzy vehicle steering control system. In general, fuzzy control system is a nonlinear control system. Therefore, the fuzzy controller may be linearized by the use of describing function first. After then, the traditional frequency domain method i.e. parameter plane, is then applied to determine the condition of stability when the system has perturbed or adjustable parameters. A systematic procedure is proposed to solve this problem. The stability problem under the effects of plant parameters and control factors are both considered here. Furthermore, the effect of transport delay is also addressed. The limit cycles provided by a static fuzzy controller can be easily suppressed if the system parameters are chosen properly. Simulation results show the efficiency of our approach.